Assig-hoes



Oct. 9, 1928.

A. H. CANDEE ET AL METHOD OF AND MACHINE FOR CUTTING CYLINDRICAL GEARS 2 Shveets-Sheet Filed Nov. 2, 1926 INVENTORS Zlarz l 'arzdee ATTO Oct. 9, 1928.

A. H. CANDEE ET AL METHOD 0F AND MACHINE FOR CUTTING CYLINDRICAL- SEARS Filed Nov. 2. 1926 2 Sheets-$heet 2 VENTORS Hllal H. C'azzdee Patented Get. 9, i925.

UNITED ALLAN H. CANDEE AND MAGNS J'SON, O? ROCHESTER, .NEV Af' TO GLEASON WGRKS, 0F ROCHESTER, h TE'W' YGRI, A CORGR- TN NET HEETHOD OF AND tIAClE F035, CUTTNG CYLINDRCL GEARS.

Application alec november 2,

The present invention relates to gears and primarily to a method and machine tor producing` spur, helical, and double helical or herringbone gears.v

The primary object ot this invention is to provide an improved method for cutting` spur, helical and double helical or herringbone gears in a. continuous planing process and to furnish a machine capable ot carrying outthe new method.

lWhen a tool is reciprocated in a straight path across the face ot a cylindrical gear blank which is rotated continuously and at a uniform velocity on its axis, a helical slot will be cut in the blank. rlhe rotation of the blank While the tool is out ot cutting` oosition vand during the time it is being` returned to its initial position preparatory to another cut, Will cause the blank to be automaticaily and continuously indexed.k rEhis method of producing helical gears has certain marked advantages, particularly for large size gears, among which are chiefly the economy in tool cost over processes in which a Worm hob is employed, and the` increased accuracy of tooth spacing, the reduction cutting time and the structural simplilication over methods and machines employing intermittent 5-*- deXing.

The advantages of the continuous planing` process in the production of gears et the type described have been long realized, but ne tooth curve resulting` trom the methods heretotore proposed tor practicing this process has hadsuch practical limitations and drawbacks, that the process itselrn has never come into general use. ln the methods heretotore proposed for cutting these gears, the motions which is was contemplated employing, were the reciprocatory motion of the tool, the continuous-rotary motion of the blank and in addition a. relative rolling movement between tool and blank for the generation o'f the tooth profiles. The tool reciprocations ivere to be obtained from a cra-nk or equivalent Inechanical means.

Non' the. motion imparted to a pla Ai i, by a crank is at a variable velocityu'hich combined with the continuousrotary motion of' the blank will produce a tooth on the-blank which is longitudinally et sinusoidal curvature, that is. a tooth of general Qs-shape.

Gre/ars having teethV ot S-shape lack ment, the S-shaped character ot the tooth curves will not permit ot' any relative axial adjust- 925. Serial LTO. 145%33.

movement between mating gears and the `gears consequently cannot accommodate themselve to. iai-ying conditions of ordinary .i many cases, moreover, because ot' the character of curve produced, the tool clearance angle will change considerably as the tool *novos across the tace oi the blank in cutting` the gear and this may cause interference between the tool and the side of tooth opposite that being` cut or may cause chatter- G5 ingr or a poor dni-sh on the surface being cut. All these dihculties are avoided in the present invention. The tooth curves can be ia lhed exactly or closely as desiree; the rs are capable ot adjustment; and the tool clearance in cmting` them will remain e' lly constant throughout the cut. .civic/n, vrith the present method, the f 'no' can he concentrated anywhere ace oi" the tcetl 75 rllhc motion imparten to a planing tool by a crank a variable velocity motion of a simple harmonic nature,the tool moving` fastest at the middle ot the stroke and slower toward each end. fe have discovered that by in parting); another relative variable velocity iifietien between the tool and blank in addition to the relative motions heretofore emjed, also oit a harmonic ire, but pret- 'l ,.rom the har- S0 can he cut motion et the tools.

p, nt in vef-ntion contcm )late tl forer` rec nccmA no the too e ot the blank vvhi .ictati k tinuoasly on its axis nmltaneously imparting' motion at a variable velocit` -ncit'eat a. harmonic nature. betvvczfn tool an"y is desired to generate "75 the proi ies any usual or snit-"ble rolling' motim` may of course, also be employed. The added varialile veiocity harmonic motion. new with this invention, may be inirirted to the tool or blank in any one of e ways: by an added rotation of the e variable velocity to combine with ontinuous uniform rotary movement crore employed; (2) by an' added variaole velocity movement to be imparted directly to the tool and to be combined with the reciprocating movement caused by the crank; and by an added relative movement between the tool and blank at a variable velocity on the basic rack or other basic member with which the blank is theoretically rolled to generate the tooth profilesthis lastmotion may be combined with the generating motion itself.

The present application is a continuation in part of our copending application, Serial No. 70,86%, tiled November 23, i925.

The accompanying drawings illustrate diagrammatically the features underlying this invention and show one embodiment of a machine for practicing` theinvcntion, said embodiment, constituting, however, but one of the various mechanical forms in which the principies of the invention be embodied.

In the drawings:

Figure 1 is side elevation, with parts broken away, of a machine constructed according to one embodiment of this invention; i

Figure 2 is a plan view, partly in section, of the machine shown in Figure l.

Figure 3 is a front elevation of the tool mechanism of this machine;

Figures e and 5 are details of the tool mechanism Figures 6 and GL are diagrammatic views,

illustrating the forms of curve produced through the various harmonic motions employed in the machine and process of this invention; and

Figure 7 is a diagrannnatic view, illustrating the curve resulting when these niotions are combined.

In producing gears according` to this invention, the tool is reciprocated by means of a crank or equivalent mechanical element, the blank is rotated continuously on its axis at a. uniform velocity, and simultaneously an additional relative movement at a variable velocity is in'iparted between tool and blank by means of a crank, eccentric, or other device for producing a variable velocity motion. The principles underlying the present invention are illustrated diagrammatically in Figures G, (3a and 7, where the curves produced by the various motions employed are shown in development.

Figure G shows the curve produced where a tool is moved by a crank across t ie face of a continuously rotating gear blank. In this ligure, C .represents the circle on which the crank pin moves. As the tool moves across the face of the blank under actuation of the crank, the blank, shown in development at B rotates on its axis at a uniform velocity. The vertical lines a, Z), o, etc. indicate the various positions of the blank due to its uniform rotation, while the horizontal lines taken by the tool in the same period under actuation of the crank. The curve produced by these two motions is shown at S. It is a curve of double iniiection, being curved in opposite directions each side of the point P. The dottedline extensions at each end of the curve indicate the path taken by the tool after it hasbeen 'lifted or clapped out of cutting position and is being returned to its initial position for cutting a new tooth space. 'lhecontinuous rotation of the blank during this idle movement of the tool serves, as a .'eady described, to index the blank. No complicated index mechanism is necessary; if there is any tool wear it is distributed cqually over all the teeth and extreme accuracy in tooth spacing is achieved'. Figure Ga shows the curve which might be produced upon' a blank when the tool is reciprocated at a variable-velocity by means of the crank across the face of the blank and when an additional relative movement at a variable velocity is imparted, as by means of an eccentric or crank, between tool and blank. The motion of the eccentric or second crank will preferably be at twice'the frequency of the harmonic motion ofthe tool under actuation of the crank, as it has been found that such a combination gives the most desirable results as regard tool clearance and longitudinal tooth curvature. The eccentric or second crank is indicated diagrammatically at E. The horizontal lines as before indicate the various positions taken by the tool under actuation of the crank, while the vertical lines o', indicate the relative moven'rent that takes place lbetween thc tool and blank due to the rotation of the eccentric. The curve whichwould result from these two motions is shown at D. Vhen the motions which produce the curves F and B are combined that-is, when a tool is moved at a variable velocity across the face of al blank rotating on its axis at a uniform velocity while simultaneously Van additional relative movement at a variable velocity is imparted between tool and blank the curve F will result, shown in Figure 7. liv properly adjusting the throw of the eccentric or second crank a curve F may be obtained which, as shown, will be substantially straight in its main portion in development. By changing the angular adjustment of the second crank orv eccentric iso lua

ii o

in cutting the two members of a pair theY n isa CII

tion may be cut with or without a generating motion, as desired. This motion, however, has no effect on the longitudinal tooth curve produced.

In the machine illustrated in the accompanying ydrawings and forming one embodiment of a mechanism for .carrying into effect this invention, the additional variable velocity movement is produced in the third way described above7 namely, by a relative move` ment of tool and blank at a variable velocity along the basic member with which during the generating operation the blank is theoretically rolled. In this machine, therefore, the tool is reciprocated at a variable velocity across the face of the blank in a plane parallel to the blank axis; the blank is rotated on its axis at a uniform velocity; a relative rolling motion is imparted between tool and blank to generate the tooth profiles; and simultaneously a further relative movement is imparted between tool and blank at a variable velocity in the manner of a gear moving at a variable velocity on the basic member with which during the generating operation the blank is theoretically rolling.

The machine illustrated is for cutting herringbone gears and two planing tools are employed, cutting from opposite sides of the blank toward the center. This machine might, however, be used for cutting single helical gears and in this case only one tool would be required. As in other planing machines, the tools cut during theirY move- .i ment in one direction only, being out of cut ting position on the return stroke.

Referring now to the figures of the drawings illustrating the machine, 10 indicates the main drive shaft which may be driven from anyv suitable source of power as by means of the pulley 11. The shaft 10 is journalled in suitable bearings in the frame or base 12 of the machine and carries near the end removed from the pulley 11, a spur gear 13. The gear 13 meshes with a spur gear 14 on a stub shaft 15 journalled in a quadrant 15 and the spur gear 14 meshes in turn with another spur gear 16 secured to the shaft 17 which is also journalled in the frame. The gears 13, 14 and 16 serve, therefore, to transmit the rotation of the mainV drive shaft 10 to the shaft 17. These gears form aset of speed change gears governing the speed of rotation of the crank which actuates the tool.

The shaft 17 drives a vertical shaft 18 through a pair of miter gears 19. The shaft 18 has a splined connection with a bevel pinion 2O which isl mounted in a suitable bearing in a slide or carrier 21. The pinion 2O meshes with a bevel gear 22 which is secured to the crank shaft 23 rotatably mounted in a suitable bearing provided upon the slide 21.

The crank shaft 23 carries at its forward end the crank plate or disc 25. The crank plate 25 is connected by means of the pin 26, and the block 27 with the tool slide 28, the slide 28 being provided with a slot 29 in its rear face in which the block 27 slides. The rotation of the crank disc reciprocates the slide 28 in the horizontal guide-Ways 30 formed on the face of the slide or carrier 21.

Secured to the slide or the carrier 21 is a face plate 32 which surrounds and houses the slide 28.v Mounted on this face plate 32 for angular adjustment thereon are a pair of guide members 33 which are formed with guide-ways 34 for guiding the tool head carriers or slides 35 in their reciprocating movement. These tool head carriers or slides 35 carry blocks 36 (Figure 4) which are swivelly connected with blocks 37 which engage in slots 38 formed in the front face of the slide 28. There areftwo slots 38 and two sets of blocks 36 and 37, one for each of the tool head carriers or slides 35. Each tool head carrier 35 carries a tool head 40, the tool head 40 being adjustable on the carriers The tool heads may be secured in any adjusted position on their respective carriers 35 by means of the bolts 41 which engage in T-slots 42 formed in the carriers 35. The tools T are carried on clapper blocks 43 which are pivotally mounted on the heads 40.

By the means described, a reciprocatory motion is imparted to each of the tools T at a variable velocity of a harmonic nature. The block and pin connection between the crank disc 25 and the slide 28 imparts a reciprocatory motion to the slide 28 as the crank disc rotates. This reciprocatory motionis imparted by means of the vblocks 36 and 37 and the slots 38 in the slide 28 to the tools. The tools shown are of the rack type, bcing provided with a plurality of cutting blades. If desired, however, a single double edged cutting tool, a single edgedy cutting tool or two single edged cutting tools may be employed. The tools may be of straight or curved profile.

The angular adjustment of the guide members 33 upon the base plate 32 permits of setting the tools so as to cut gears of different helix angles, while the adjustment of the tool heads 40 upon the-.tool head carriers or slides 35 permits of'setting the tools any desired distance apart to vary the portion of the face of the blank to be cut. The pin 26 is carried on a block 44 which is adjustable in a slot 45 formed in thek face of the crank disc 25, by means of the screw 46. This is the usual adjustment and enables the throw of the crank to be changed to vary the stroke of the tools.

The tools cut on their movement in one direction only and are clapped out of cutting 'bevel gear 5 l position on the return stroke. Any suitable .mechenien'i iney beeinployed for chipping' thetools; out of cutting position and this forms no part ot the preeent invention. Le

shown.l cachot the chipper blocks is con nectedb)v ineens ot a togggb ineniber il?) with erod' which slides in e traction bloeli 50 which is Securedto urgu'ide member DL ring the reciprocutory movement of the tools :11rd rin timed relation thereu i, tlv blunl'ie rotetedonite :1i-ie co1itiniwus'sl yv :ini

e i'uiij'orin velocit},f. rhe .necl-enism tor .w in'iperting to the blenl: contnuiioue rote 'v n'ioveuient mil now be described Secured tothe inziin drive ehei't l() interi iet-e its bevel vitl e ends is; e

i., .1. .Secured to 'which journeled in the the n echiee. rEhe erosie jacent its outer end one ii" rml genis eo ein n open,`

Shettivith e eheitt el which is; 'jo nel in thefrai'ue. The.. shaft -l carries; at outer end u spur geur 55. f The spur geen l nie'shes f1 ur generating the tooth pro'lee rfid in this meu chino the -zidditionel ve. ii: l le velocitj,7 movemeut, new. ,with thie invention7 .iss1 produced. by imparting :i variable velocity movement ietu'een *d ol and blenl; on the beeic your with which the bh nl: is theoreticellj.Y rolled rto gene'nte the Vtooth prolilee.` ln the nmchiue, illustrited. the ege-i ereting motion comprises e reletive roliine movement e tween tool und blsjinl; 'in the meiner or e freer i'neshiup' with u rack and is: obtained oy iinperting a Slow iuo\.f'enie,it ot trznslatiou to the carrier or slir'le fl continuouelv in one direction during' outline ot the blunl. The ineens; for imparti if to the elide or currier 2l the movement nezeerj to ogenerzife the tooth prolilee will. first be described.

The Slide or carrier 2l moves on guide Ways T0 :formed on :t eten/lard the tools 'll in e. direction tei' h surface et i n1( veulent b e gear rolling ie occured in ui 'f pr u relative blank is olf Stendard 7l, ner 'to the bese l2.

ment of the slide 2l ie produced bynievv; ot the eieren* which otutee ii l i i i?, e cured to the` eli'le 2l. Rotary niovenieiit ie -ton with 'the imparted/to the"v by ineens of 'e bevel. geen: 71 wvl.. e Splined connecon "5 which outer en d e..

)on e quadrant tid. ee u edfspur eu' ol 'i epur geur S2 which ie c shaft which il, jouru" ,f :uid which is dri 'en e nein drive Sheit l() by i eet of pitch or ratio change governing relative rolling nievetool audblenk. `redetermined timed relation must be ined bew ei the tool reciprocetion blunl; rotation in order that the teetl L spaced on the blank. The treneetorv niov nient imparted to the tools; by nenne of the carrier or elide 21 Would dis- ;irb this predetermined tin'ied relation unmenue were provided to compen- Cheng-ge gemis mightlbe enil iie jlviurporie, but these would renire coneidereble calculation and a. chen o ot -nibineft constitute e und be pro .ierlj l ion with erichy change Ain the `rete o't .oil or h oi the teeth. Preferably,

therefore.' e dl''brei ul employed. 'The differential hes the advantage ot' permitting env d red pitch oit teeth "to be out While elwervf; in ei..rtei.ning the proper timed rel( ti n between the tool and l lunl-;. The d ifiern entiul, moreover7 will always impart the exact cou1pe1i:-'f:1ting motion required and no iinzlti n is nee-eeearv ne would be the in many inc-'stances'. Where the celculatfoul-e 'would have e "fractional approx.A

number ot 'teeth and could only be z gproxi- :noted by gears having` the nearest inteeg'rel i'iunibe: et' teeth. T 1e didiereiiitiel eers `53 serve, the compensati? to 'incr/eme or decreoer. une rot to coiiipeiiseteuif the t 'unehitory movement o the'tools.

The con'ipensetingr motion 'ie en .from the ehzit't 76 bj.' moana ot the ini goers S53 end S6., one which ifs secured vto the i1 lther olf 'which .ie Secured to :Vt TG sind the.

i c 8T which is "e TAnailed in :wie beu'nos in the 3: lhe Shaft carries uter end 88 flies.' with e miler 89 fed to the Q0, Th cro-Se lc-erriee e outer ci se nii shaft 9 1d e spur een. r G53 ufhicn i.. Gil 'which is Secured lill'erentizil. genre the mechanism mechanism 'v movement nnpmfting a ineens rot inech eniein fr bien is journ'all'ed i relative rolling movement between the tool and blank by translation of the tool and the means for compensating for this translatory movement to maintain the timed relation between the tool reciprocation and blank rotation. `To these motions there is added, in the pieseiit invention, a further relative movement between tool and blank at avariable velocity, which is produced in the machine shown by a reciprocatory movement of the slide or carrier 21 at a variable velocity. This reciprocatory movement `is produced by means o-f a crank 92 which is mounted .on

a shaft 93 journalled in the base `12and which is connected by means of the crank pin 94 and slot 9 5 with a head 96 which is swivelly secured to the lower end of the elongated shaft which carries the screw 72.V The' amount of throw of the crank 92 can be adjusted by any Vusual or suitable means for different pitches of teeth. |The crank 92 acts to impart to the elongated screw shaft 72 a reciprocatory movement, at a variable velocity which in turn is imparted to the slide or carrier-21. The shaft 72is,as previously described, splined for a portion of itsl lenth so that it can reciprocate under im* ulse of the crankv 92 while beine' rotated .y adjustment of the guide members 38. The

through rotation of the bevel gearfll.' lThe combined reciprocatory and rotary motion L of the shaft r2 acts to impart to the carrier or slide 21a movement which is a resultant of the rolling motion necessary to generate the toothV profiles and of the additional variable velocity moveinent which co-acts with the reciprocatory movement of the tool and' the continuous rotary'motion of the blank. to form the longitudinal tooth curve. Y

The crank 92 is driven preferably, at twice the speed of the crank 25, being rotated from the main drive shaft by the spur gears 97 and 98, l

During the generation of a gear, therefore,

Va reciprocatory movement will be imparted Qto the tool or tools in timed relationwitli the rotary movements imparted to the blank and simultaneously a movement will be iin- 'parted to the carrier or slide'21 which is a resultant of the combined rotary and reciprocatory movements of the screw shaft 72. The tools may cut on successive strokes in successive tooth spaces or, if desired, may skip a number of tooth spaces between strokes. TVith the present machine, however, the skipping' of a number of tooth spaces is not necessary, since aiiydesired helix angle can be obtained by theangular combined motion iinparted'to the slide or carrier 21 will `Aact to gradually move the slide 21 up `or down on the standard 71. After a blank has been completely generated, the slide 21 may be returned to its initial position for cutting a new blank. F or -this purpose, the shaft 76 may be rotated in a reverse direction by'hand, or, if desired, any suitable type of reversing mechanism may be employed.

The present machine may be employed for roughing ory finishing. During the roughing operation, the ratio change gears may be disconnected so that the only movement imparted to the slide 21 is the reciprocatory movement due to the crank 92. For roughing, a feed movement is required to move the blank relative to the tools so that they can cut to the proper depth. For this purpose, in the present machine the blank spindle (Si is journalled in suitable bearings on'a slidable head 100. The head 100 may be fed toward the tools by means of the screw 101 which may be driven automatically, or, as shown, may be rotated by hand. F or the iinishingcut, no feed movement is required' and the blank head may be secured to the blank head carrier 102, which is mounted on vthe base 12, by means of the bolts 103 which take into `l"`slots 104e provided in the carrier 102.

lJVhile particularly applicable to the production of spur, helical and double helical or herringbone gears, the present invention may be employed, also, in the cutting of internal gears. e

ln general, it may be said, that while we have Vdescribed our invention with reference to a particular embodiment, it is to be understood that the invention is capable of various further modifications and uses and that this application is intended to cover any adaptations, uses, following in general, the principles of the nvention including suoli departures from the present disclosure as come within known or customary practise in the gear art and may besapplied to the essential features hereinbefore set forth and as fall within the scope of the invention or the limits of claims.

Having thus described our invention what we claim is:

l. lThe method of producing gears, which consists in moving a tool at a variable velocity across the face of a cylindrical blank in a plane parallel to the ax's of the blank, while rotating the blank continuously on its axis a uniform velocity and simultaneously imparting an additional relative movement between the tool and blank at a variablevelocity, which combined with the other motions will produce the longitudinal tooth form.

rhe method of producing gears which consists in moving a tool at a variable velocity of a harmonic nature across the face of a rylind'rical blank in a plane parallel to the blank axis, while rotating the blank continuously on its axis at a uniform velocity, and simultaneously imparting an additional relative movement between the tool and l'or embodiments of the invention,

the appended ico blank at va variable velocity also of `a yharmonic nature,.said last named movement acting in conjunction with the other movements to produce tlie ylongitudinal'tooth form.

3. The method of producing gears which consists invmoving a tool at a variable velocity of a harmonic nature across the face of a cylindrical blank in a plane parallel :to the blank axis, while rotating the blank continuously on its axis at a uniform velocity, and simultaneously imparting an additional relative movement between the tool and blankat aV variableJ velocity also of a harmonic` l,nature but of a dili'erent frequency from the first harmonic motion, said last named movement acting in conjunction with the other movements to produce the longitudinal tooth form.

4;. The method of producing a gear which consists in moving a tool at a variable velocity of a harmonic nature across the face of a cylindrical blank in a plane parallel to the blank axis, while rotating ,the blank continuously on its axis at a uniform velocity, and simultaneously .imparting an additional relative movement between the tool and blank at a variable velocity also of a harmonic naturc,fbut` oftwice the frequency of the first harmonic motion, said last named movement ,acting in conjunction with the ot-her movements to produce the 'longitudinal tooth form.

5. The method of producing a gear which consists in moving a tool, at a variable velocity, across the face of a cylindrical gear blank in a plane parallel to the blank axis, while rotating the blank on its axis continuously at a uniform velocity, simultaneously imparting an additional relative movement betweenY tlieptool and blank at a variable velocity to produce the longitudinal tooth shape and continuously index the blank, and simultaneously producing a relative rolling motion between the tool and blank at a. uniform velocity to generate the tooth proliles.

6. The method of producing a gear which conists in moving a tool, at a variable velocity, across the face of a cylindrical gear blank in a plane parallel to the blank axis, While rotating the blank on its axis continuously at a uniform velocity, simultaneously imparting an additional relative movement between the tool and blank at a variable velocity to produce the longitudinal tooth shape and continuously index the blank, and simultaneously producing a relative rolling motion between the tool and blank at a imiform velocity in the manner of a gear rolling on .a rack to generate the tooth profiles.

7. The method of producing a gear which consists in moving a toolat a variable veloc ity of a harmonic nature, across the face of a cylindrical gear blank in a plane parallel to the blank axis, while rotating the blank on its axis continuously at a uniform'velocity,

harmonic motionto produce the longitudinal tooth shape and continuously index the blank, and simultaneously producing a relative rolling motion between the tool and.

blank at a uniform velocity to generate the tooth profiles.

n 8. The method of producing a gear which consistsin moving a tool, at a variable velocity of .a harmonic nature, across thc face of a cylindrical gear blank in a plane parallel tothe blank axis, while rotating the blank on its axis continuously at a uniform velocity, simultaneously imparting an additional relativemovement between the tool and blank at a variable velocity, also ofa harmonic nature butof a di-ferent frequency from the lirst harmonic motion to produce the longitudinal tooth shape andcontinuously index the blank, and simultaneously produc'ng a relative rolling motion'between the tool and blank at a uniform velocity in the manner of a gear rolling on a rack to generate the tooth profiles.

.9. The method of producing a gear which consists in moving a tool, at a, variable veineity, across the face of a cylindrical gear blank in `a plane parallel to the blank axis, while rotating the blank continuously on its axis at a uniform velocity, and simultane-- ously imparting between the tool and blank a continuons translatory movement at a variable velocity in a direction tangential to the pitch surface of the blank. v

10. The methodof producing a gear which consists in moving a tool, at a variable velocity of a. harmonic nature, across the face of cylindrical gear blank in a plane paralleleto the blank axis while rotating the blank continiiously on its axis'at a uniform velocity,

and simultaneously imparting between tool and blank a continuous translatory inovcing the tool at a variable velocity across the d face of the blank in a plane parallel to the, blank axis, means for imparting a continu-l ous rotary movement at a. uniform velocity to the blank spindle, and means for simultaneously imparting an additional relative movement at a variable velocity between tool and blank lto produce in combination with the other movements the longitudinal tooth form.

l2. .In al machine for producing cylindrical gears, a tool support, a tool mounted ture across the face of the blank in a plane parallel to the blank axis, means for imparting a continuous rotary movement at a uniform velocity to the blank spindle, and means for simultaneously imparting an additional relative movement between tool and blank at a variable velocity also of a harmonic nature but of a different frequency from the first harmonic motion to produce in combination with the other movements the longitudinal tooth form.

13. In a machine for producing cylindrical gears, a tool support, a tool mounted thereon, a. blank support, a blank spindle journaled therein, means for moving the tool at a variable velocity across the face of the blank in a plane parallel to the blank axis, means for imparting a continuous rotary movement at a uniform velocity to the blank l spindle, means for simultaneously imparting an additional relative movement between the tool and blank at a variable velocity, said last named motion combining with the before mentioned movements to produce the longitudinal tooth shape and means for simultaneously producing` a continuous `relative rolling motion between the tool and blank to generate the-tooth profiles.

14. lIn a machine for producing cylindrical gears, a tool support, a tool mounted thereon, a blank support, a blank spindle journaled therein, means for moving the tool, at a variable velocity of a harmonic nature, across the face of the blank in aplane parallel to the blank anis, means for imparting a continuous rotary movement at a uniform velocity to the blank spindle',

vmeans for simultaneously imparting an additional relative movement between-the tool and blank at a variable velocity'alsoof a harmonic nature but of a different frequency from the first harmonic. motion, said last 'named motion combining w'th the before mentioned movements to produce the longitudinal tooth shape, and means for simultaneously producing a continuous relative rollingmotion between the tool and blank at a uniform velocity to generate the tooth profiles. Y

,15.,In a machine for producing cylindrical gears, a tool support, a. tool mounted thereo-n, a blank support, a blank spindle jourrnaled therein, means for moving the tool at a variableV velocity across the face of the blank Vin a plane parallel to the blank axis,

means for imparting a continuous rotary movement at a uniform velocity to the blank spindle, means for simultaneously imparting an additional relative movement between the tool and blank at a variable velocity, said last named motion combining with vthe be- `blank at a uniform velocity'in the manner of a gear rolling on a rack to generate the tooth profiles. f

16. In a machine for producing cylindrical gears, a tool support, a tool mounted thereon, a blank support, a blank spindle journaled'therein, means for moving the tool at a variable velocity of a harmonic nature across the face of the blank in a plane parallel to the blank axis, means for imparting a continuous rotary movement at a uniform velocity to the blank spindle, means for simultaneously imparting van additional relative movement between the tool and blank at a variable velocity also of a harmonic nature but of a different frequency from the lirst harmonic motion, said last named motion combining with the before mentioned movements to produce the longitudinal tooth shape, and means for simultaneously producing a continuous relative rolling motion between the tool and blank at a uniform velocity in the manner of a gear rolling on a rack to Vgenerate the tooth profiles;

-17 In a machine for producing cylindrical gears, a` tool support, a tool mounted thereon, a blank support, a blank spindle journaled therein, a carrier upon which one of said supports is mounted, means for moving the tool at a variable velocity across the Vface of the blank in a plane parallel to the blank axis, means for imparting a continuous rotary movement at a uniform velocity to the blank spindle, land means for simultaneously imparting movement to said carrier at a variable velocity, said last named motion combining with the before mentioned movements to produce the longitudinal tooth shape.

18. In a machine for producing cylindrical gears, a tool support, a tool mounted thereon, a. blank support, a blank spindle journaled therein, ay carrier upon which one of said supports is mounted, means for moving the tool at a variable velocity of a harmonic nature across'the face of the blank` thereon, a blank yjournaled therein,

f 26. In a machine for producing cylin-V drical gears. a tool support, a tool mounted support, a blank spindle a carrierY upon Which one of said supports is mounted, means for moving the tool at a variable velocity across the face of the blank in a plane parallel to the blank axis, means for imparting to the blank spindle a continuous rotary movement at a uniform velocity, means for imparting to said carrier a uniform velocity movement to generate the tooth proiiles and means for simultaneously,imparting to said carrier a variable velocity movement, said last named movement combining with the tool motion and thepuni'form rotation of the blank to .produce the longitudinal tooth shape.

27. ln a 'machine for producing cylin` drical gears, a tool support, a tool mounted thereon, a blank support, a blank spindle journaled therein, a carrier upon which one of said supports is mounted, means for moving said tool at a variable velocity of a harmonic nature yacross the face of the blank in a plane parallel to the blank axis, means for imparting to the blank spindle a continuous rotation-at a uniform velocity, eans for imparting to said carrier a uniform velocity movement in a direction tangential to the pitch surface of the blank, and means for simultaneously imparting to said carrier a variable velocity movement of a harmonic nature but of a frequency dierent from the firstharmonic movement in the direction last described.

28. In a machine for producing ycylindrical gears, a tool support, a tool mounted thereon, a blank support, a blankspindle journaled therein, a carrier upon Which one of said supports is mounted, means for moving the tool across the face of the blank in a plane parallel to the blank axis at a variablervelocity of a harmonic nature, means for imparting to the blank spindle a continuous rotation at a uniform velocity, means forrimparting to said carrier a variable velocity movement of a "harmonic nature but of a different frequency from the first harmonic movement, said last named` movement combining with the before mentioned motions to produce the longitudinal tooth shape and means for simultaneously imparting to said carrier a uniform velocity movement to generate the'tooth profiles.

29. In a machine for producing cylindrical gears, a tool support, a tool mounted thereon, a blank support, a blank spindle iournaled therein, a carrier upon which one of said supports is mounted, meansfor moving the tool across the. face of the blank in a plane parallel to the blank axis at a variable velocity, meansy for impartingl to the Vblank spindle a continuous rotary movement uniform velocity, means for i i 'l between t-ool and blank at a variable velocity, said last named motion combining with the beforementioned movements to produce the longitudinal tooth shape, means for continuously imparting movement to said carrier at a uniform velocity to generate the tooth protiies, and compensating means for maintaining a timed relation betweenv the blank rotation and tool movement during the movement of said carrier.

30. ln a machine for producing cylindrical gears, a. tool support, a tool mounted thereon, a blank support, a blank spindle journaled therein, a carrier uponwhich one of said supports is mounted, means for moving the tool across the face of the blank in a plane parallel to the blank axis at a variable velocity of a harmonic nature, means for imparting to the blank spindle a continuous rotary movement at a uniform velocity,

means for producing an additional relative movement between the tool and blank at aV variable velocity of a harmonic nature but of a different frequency from the lirst harmonic movement, said last named movement combining With the beforementioned motions to produce the longitudinal tooth shape, means for continuously imparting to said carrier a movement at a uniform velocity to generate the tooth'proiles, and compensating means for maintaining a timed relation between'the blank rotation and the tool movement during the movement of said carrier.

3l. ln a machine for producing cylindrical gears, a tool support, a tool mounted thereon, a blank support, a blank spindle journaled therein, a carrier upon which one of said supports is mounted, means for moving the tool vacross the face of the blank in a plane parallel to the blank axis at a variable velocity, means for imparting to the blank spindle a continuous rotary movement at a uniform velocity, means for imparting an additional relative movement between tool and blank at a variable velocity, said last named motion combining-with the before mentioned movements to produce the longitudinal tooth shape, means for imparting` a continuous translatory movement at a uniform velocity to said carrier in a direction tangent to the pitch surface of the blank and compensating meansfor maintaining a timed relation between-the blank rotation and tool movement during the movement of said carrier.

32., In a machine'for producing cylindrical gears, a tool support, a tool mounted thereon, a blank support, a blank spindle journaled therein, a carrier upon which one of said supports is mounted, means for reciprocating the tool across the face of the blank in a plane parallel to the blank aXis at a variable velocity of a harmonie nature, meansrfor impart-ing to the bl spindle' a continuous loo lll)

Vtinuous translatory movement in a plane tangent tothe pitch surface of the blank, and compensating .means for maintaining a timed relation between the blank rotation and tool reciprocation during the movement of said carrier.

33. In a machine for producing cylindrical gears, a tool support, a tool. mounted thereon, a blank support, a blank spindle journaled therein, a carrier upon which one of said supports is mounted, means including a crank and connecting rod for reciproeating the tool a variable velocity across the face of the blank in a plane parallel to thev blank axis, means for imparting a continuous rotary movement to the blank spindle at a uniform velocity, a screw operative- Vly connected with said carrier, means for continuously rotating said screw to impart vto said carrier a translatory movement in a plane tangent to thepitch surface of the blank, compensating mechanism for maintaining a timed relation between the tool reciprocation and blank rotation, and means for imparting an additional relative movement at a variable velocity between the tool and blank said lastnamed movement c`ombining with tool motion and blank rotation to produce the longitudinal tooth shape.

3a. In a machine for producing cylindrical gears, aV tool support, a tool mounted thereon, a blank support, a blank spindle journaled therein, a carrier upon which one of said supports is mounted, means including a crankand connecting` rod for reciprocating the tool at a variable velocity across the face of the blank in a plane parallel to the blank axis, means for imparting to said blank spindle a continuous rotary movement at a uniform velocity, a screw operatively connected with said carrier, means for continuously rotating said screw to impart to said carrier a translatory movement in a plane tangent to the pitch surface` of theblank, compensating mechanism formaintaining a timed relation between the tool reciprocation and blank rotation, and means lfor simultaneously imparting a reciprocatory movement at a variable velocity to said carrier, said last named movement combining with the tool motion and blank rotation to produce the longitudinal tooth shape.

35. In a machine for producing cylindrical gears, a tool. support, a tool mounted thereon, a blank support, a blank spindle journaled therein, a carrier upon which one of said supports is mounted, means including a crank and connecting rod forA reciprocating the tool at a variable velocity across the face of the `blank in a plane parallel to between the tool reciprocation yand blank rotation, and means for simultaneously reciprocating said screw at a variable velocity of a harmonic nature, but of a different fre.

quencv from the movement of the crank.

36. The method of producing a gear which consists in giving a tool a straight line reciprocating cutting motion at a variablevelocity in a plane parallel to the axis of the blank while rotating the blank continuously on its axis at a uniform velocity and simu taneonsly impar ing an additional relative movement between the tool and blank at a variable velocity which combined with the other motions will producel longitudinal tooth shape. i

37. The method of producing .a gear which consists in givingY a tool astraight line reciprocating cutting motion at a variable velocity of a harmonic nature in a vplane parallel to the axis of the blank while rotating the blank continuously on its axis at a uniform velocity and simultaneously imparting an additional relative movement between the tool and blank at a variable velocityalsol of a harmonic nature, said last named .movement combining with the other motions to produce the longitudinal tooth shape.

38. The method of producing a gear which consists in giving a` tool a straight line reciprocating cutting motion at a 4variable velocity in a plane parallel to the axis of a cylindrical gear blank while rotating the blank on its axis atauniform velocity and simultaneously imparting an additional relative movement between the tool and blank at a variable velocity, said last named m0vement combining with the before mentioned motions to produce the longitudinal Vtooth shape, and simultaneously producing a relative rolling motion between the tool and blank to generate the tooth profiles.

39. rIhe method of producing a gear which consists in giving a tool a straight linereciprocating cutting motion at a variable velocity of a harmonic nature iny a plane parallel to the axis of a cylindrical gear blank, while rotating the blank on its axis continuously at a uniform velocity and simultaneously imparting an additionalrelative movement between the tool and blank at a variable velocity of a harmonic nature but of a different frequency from the variable` motion of the tool, said last named motion combining with the before mentioned motions to produce the longitudinal tooth shape, and simultaneously producing a relative rolling motion between the tool and blank to generate the tooth profiles.

40. In a machine for producing cylindrical gears, a tool support, a tool mounted thereon, a blank support, a blank spindle journaled therein, means including a crank for reciprocating the tool at a variable velocity across the face of the blank in a plane parallel to the blank axis, means for imparting a continuous rotary movement at a uniform velocity to the blank spindle and means for simultaneously producing an additional relative movement at a variable velocity between the tool and blank, said last named movement combining with the before mentioned motions to produce the longitudinal tooth shape. l

41. In a machine for producing cylindrical gears, a tool support, a tool mounted thereon, a blank support, a blank spindle journaled therein, means including a crank for reciprocating the tool at a variable velocity across the face of the blank in a plane parallel to the blank axis, means for imparting a continuous rotary movement at a uniform velocity to the blank spindle, and means for simultaneously producing an additional relative motion at a variable velocitybetween the tool and blank, said last named motion combining with the before mentioned movements to produce the longitudinal tooth shape, and means for simultaneously producing a relative rolling motion between the tool and blank to generate the tooth profiles.

ALLAN H. CANDEE. MAGNUS H. J CHANSON. 

